Stable salad dressings

ABSTRACT

The present invention provides a stable foodstuffs which contain a cholesterol lowering amount of a sterol or stanol ester, crystal fat inhibitors and emulsifiers. The foodstuffs, including salad dressings are stable even when refrigerated.

FIELD OF THE INVENTION

This invention relates to stable salad dressings containing a sterol ester and methods of producing the same.

BACKGROUND OF THE INVENTION

It has been shown that the addition of plant sterols, such as β-sitosterol, to diets will reduce serum cholesterol levels. The sterols reduce serum cholesterol through the disruption of intestinal absorption of dietary cholesterol by displacing it from bile acid micelli. More recently, β-sitosterol's saturated derivative, β-sitostanol, has been shown to be more effective in the reduction of intestinal cholesterol absorption. The sitostanol itself is virtually unabsorbed, so it does not contribute at all to in vivo serum sterol concentration upon consumption. Unfortunately, typical sterols and stanols are insoluble in the micelli phase of the alimentary canal and have only limited solubility in oils and/or fats or water. Hence, free sterols or stanols themselves are not optimum candidates for use in typical pharmaceutical or dietary dosage forms as cholesterol reducing agents.

The incorporation of these materials into foods are also difficult due to the limited solubility of the stanol or sterol in foods such as margarine and salad dressings. Salad dressings are particularly difficult in that they are frequently sold at room temperature, but require refrigeration after opening. Formulating a stable composition is particularly difficult when changes in temperature occur.

SUMMARY OF THE INVENTION

The present invention is directed to a stable food containing a cholesterol reducing amount of a sterol ester; an effective amount of a fat crystal inhibitor, and an effective amount of a hydrocolloid stabilizer or emulsifier. In a particularly preferred embodiment the present invention is a salad dressing which remains stable even when refrigerated.

DETAILED DESCRIPTION

As disclosed in U.S. Pat. Nos. 5,502,045, 5,578,334 and 5,244,877, the contents of which are incorporated herein by reference, it is known that consumption of β-sitosterol is known to reduce cholesterol levels in the blood stream. In order to be effective it is necessary to consume from about 0.5 to about 1.5 grams, and more preferably about 1 gram of β-sitosterol per serving size. The word sterol ester as used in the present invention is understood to include any cholesterol lowering agent including stanols, stanol esters, sterol esters and the like.

In order to incorporate an effective amount of β-sitosterol in a salad dressing, in which an average serving size of about 30 grams, it is necessary to incorporate less than about 10 percent by weight, typically less than about 8 percent and most preferably about 6 percent by weight of the β-sitosterol in a salad dressing serving.

At this relatively high level of β-sitosterol, it is difficult to formulate a stable product, especially after the product has been opened and requires refrigeration. Refrigeration as used herein, is understood to be temperatures below room temperature, which includes about 60 F., but the term also includes temperatures of 40 F. and below. These lower temperatures are commonly found in commercial and residential refrigerators.

As used throughout this application, stable is understood to mean that the product does not separate into different phases. Instead the food, most preferably the salad dressing, will be relatively uniform and not separate into distinct layers. An example of a stable system is a salad dressing which remains creamy after a period of time. An example of an unstable system is an Italian salad dressing which after the passage of some time will separate into two distinct regions, an oil phase and an aqueous phase.

The present invention requires the incorporation of an effective amount of fat crystal inhibitors which include polyglycerol esters of fatty acids, sorbitan esters of fatty acids such as sorbitan tristearate; polysorbates made from the reaction product of monoglycerides or sorbitan esters with ethylene oxides, mixtures of these materials and the like. Examples of useful polysorbates include polyoxyethylene 20 mono- and diglycerides of saturated fatty acids, polyoxyethylene 4 sorbitan monostearate, polyoxyethylene 20 sorbitan tristearate, polyoxyethylene 20 sorbitan monooleate, polyoxyethylene 5 sorbitan monooleate, polyoxyethylene 20, sorbitan trioleate, sorbitan monopalmitate, sorbitan monolaurate, propylene glycol monolaurate, glycerol monostearate, diglycerol monostearate, glycerol lactyl-palmitate; mono and di-glyerides and the like. A particularly preferred fat crystal inhibitor is Caprol ET, commercially available from A. C. Humko, which is a mixture of polyglycerol fatty acid esters. Typically these materials are incorporated at levels of from 0.1 to about 3.0 percent by weight, preferably from about 0.2 to about 2.0 and most preferably about 0.5 weight percent.

Useful emulsifiers in the practice of the present invention include polyglycerol esters, mono and diglycerides of fatty acids, propylene glycol esters, sucrose fatty acid esters and polyoxyethylene derivatives of sorbitan fatty acid esters and the like. Mixtures of emulsifiers may also be employed. These emulsifiers are well known in the art and are commercially available. The emulsifier level is typically from about 0.01 to about 1.5 weight percent, preferably from about 0.1 to about 1.2 and most preferably from about 0.5 to about 1.0 weight percent.

Suitable polyglycerol esters include triglyceryl monostearate, hexaglyceryl distearate, hexaglyceryl monopalimate, hexaglyceryl dipalmitate, decaglyceryl distearate, decaglyceryl monoleate, decaglyceryl dioleate, decaglycerol monopalmitate, decaglycerol dipalmitate, decaglyceryl monostearate, octaglycerol monoleate, octaglycerol monostearate and decaglycerol monocaprylate.

Other suitable emulsifiers include, with HLB values provided in brackets, [ ], include decaglycerol monolaurate[15.5]; decaglycerol distearate [10.5]; decaglycerol dioleate [10.5]; decaglycerol dipalmitate [11.0]; decaglycerol monostearate [13.0]; decaglycerol monooleate [13.5]; hexaglycerol monostearate [12.0]; hexaglycerol monooleate [10.5]; hexaglycerol monoshortening [12.0]; polyoxyethylene (20) sorbitan monolaurate [16.7]; polyoxyethylene (4) sorbitan monolaurate [13.3]; polyoxyethylene (20) sorbitan monopalmitate [15.6]; polyoxyethyLene (20) sorbitan monostearate [14.9]; polyoxyethylene (20) sorbitan tristearate [10.5]; polyoxyethylene (20) sorbitan monooleate [15.0]; polyoxyethylene (5) sorbitan monooleate [10.0]; polyoxyethylene (20) sorbitan trioleate [11.0]. As is appreciated by those with skill in the art, the HLB value for a surfactant is an expression of its Hydrophile-Lipophile balance, i.e., the balance of the size and strength of the hydrophilic (polar) and lipophilic (non-polar) groups of the surfactant.

Lactic acid derivatives include sodium stearoyl lactylate and calcium stearoyl lactylate.

In addition to emulsifiers, hydrocolloids may also be used to stabilize the emulsion at the same levels as the emulsifiers. Suitable hydrocolloids include xantham gum, propylene glycol alginate, guar gum, gum Tragarcanth, locust bean gum, gellan gum, gum Arabic, cellulose gums, cellulose derivatives such hydroxymethylpropyl cellulose, carboxymethyl cellulose, microcrystalline cellulose and the like; modified food starches and the like. In a preferred embodiment, both an emulsifier and hydrocolloid are employed.

Hydrocolloids are commonly used in combination with whole egg, egg yolks as well as the emulsifiers set forth above. The preferred stabilizers are combinations of xantham gum, propylene glycol alginate, egg yolk and modified food starches. However it was discovered that the incorporation of stanol esters in the formulations caused crystallization at temperatures below about 65 F. The destabilization of the emulsion was particularly noted when the amount of egg yolk was limited. In order to have the product defined as cholesterol free, egg yolk in the formulations was limited to less than 2 milligrams per serving.

The foods of the present invention also include preservatives, colorings, vitamins, seasonings and excipients which are well known to those in the art.

The present invention also provides a method for preparing a stable food emulsion comprising: providing an aqueous stream; providing an food grade acceptable oil; providing a stanol ester; providing a crystal fat inhibitor and an emulsifier; admixing said oil, stanol ester, crystal fat inhibitor and emulsifier; heating the admixture to a temperature of from about 100 to about 150 F. to form a heated oil adding the heated oil to said aqueous system. More preferably the admixture is heated to a temperature of from about 120 to about 140 F.

In order to make the salad dressings of the present invention any suitable food grade oils may be employed including soybean, sunflower, corn, vegetable and the like. The oils are typically less than 50% of the salad dressing, more preferably from about 25 to about 40 weight percent.

The following examples are provided to further illustrate the claimed invention, but not limit the invention to the examples provided below. Unless noted otherwise, all weights are presented in weight percent.

EXAMPLE 1

The following examples are examples of a stable salad dressings containing sufficient stanol esters to provide an effective amount of stanol ester to reduce cholesterol when a serving of 30 grams is used. Sorbitan tristearate could be substituted for Caprol ET or combined with Caprol ET in each of the formulations. All of the following formulations additionally contain seasoning, preservatives, coloring, flavoring as desired for taste.

    ______________________________________                                         RANCH DRESSING FORMULATION                                                                     Typical      Range of                                          Ingredients Composition                                                                        Formula      Ingredients                                       Ingredients     Percent      Percent                                           ______________________________________                                         Soybean oil, salad oil                                                                         40.000       30-50                                             Vinegar,        6.000        4.0-10                                            stanol esters   5.750        3.0-10                                            Sugar,          4.000        3.0-6.0                                           Cultured buttermilk solids                                                                     1.000        0.5-3.0                                           Caprol ET       0.500        0.2-2.0                                           Egg yolk,       0.360        0-2.0,                                            Xanthan gum     0.300        0.15-0.5                                          Polysorbate 60 (Tween 60)                                                                      0.300        0-0.30                                            Propylene glycol alginate                                                                      0.160        0.05-0.30                                         Polysorbate 80 (Tween 80)                                                                      0.160        0.0-0.30                                          Water           36.568       To 100%                                           Total           100.000      100                                               ______________________________________                                    

    ______________________________________                                         FRENCH STYLE DRESSING FORMULATION                                                              Typical      Range of                                          Ingredients Composition                                                                        Formula      Ingredients                                       Ingredients     Percent      Percent                                           ______________________________________                                         Soybean oil     35.000       25-40                                             Sugar           14.000       8.0-20                                            Vinegar         6.000        4.0-10                                            Tomato Paste (.sup.˜ 31% solids)                                                         6.000        3.0-10                                            Stanol esters   5.600        3.0-10                                            Caprol ET       0.500        0.1-2.0                                           Egg yolk        0.350        0-2.0                                             Polysorbate 60  0.300        0-0.3                                             Xanthan gum     0.200        0.1-0.5                                           Propylene glycol alginate                                                                      0.100        0-0.5                                             Polysorbate 80  0.100        0.0-0.3                                           Water           28.831       To 100%                                           Total           100.000                                                        ______________________________________                                    

    ______________________________________                                         THOUSAND ISLAND DRESSING FORMULATION                                                           Typical      Range of                                          Ingredients Composition                                                                        Formula      Ingredients                                       Ingredients     Percent      Percent                                           ______________________________________                                         Soybean oil     35.000       25-40                                             Sweet relish    10.00        4.0-15                                            Sugar           9.000        4.0-15                                            Vinegar         6.000        4.0-10                                            Stanol esters   5.600        4.0-10.0                                          Tomato paste    5.000        2.0-8.0                                           Egg yolk, liquid, 10% salt                                                                     0.400        0-1.0                                             Caprol ET       0.500        0.1-1.5                                           Polysorbate 60  0.300        0.1-0.30                                          Xanthan gum     0.300        0.1-0.5                                           Propylene glycol alginate                                                                      0.130        0.05-0.5                                          Polysorbate 80  0.100        0.0-0.3                                           Water           25.700       To 100%                                           Total           100.000      100                                               ______________________________________                                    

    ______________________________________                                         CREAMY ITALIAN DRESSING FORMULATION                                                            Typical      Range of                                          Ingredients Composition                                                                        Formula      Ingredients                                       Ingredients     Percent      Percent                                           ______________________________________                                         Soybean oil     33.000       25-40                                             Vinegar         9.200        5.0-15                                            Sugar           6.000        3.0-10                                            Stanol esters   5.750        4.0-8.0                                           Diced sweet Bell peppers,                                                                      0.600        0.2-1.5                                           dried                                                                          Caprol ET       0.520        0.1-1.0                                           Buttermilk      0.500        0-1.0                                             Eggs            0.400        0-1.0                                             Xanthan gum     0.320        0.1-0.5                                           Polysorbate 60  0.300        0-0.30                                            Modified food starch                                                                           0.250        0-1.0                                             Titanium dioxide                                                                               0.200        0-0.5                                             Propylene glycol alginate                                                                      0.160        0.05-0.5                                          Polysorbate 80  0.090        0.0-0.30                                          Water           37.330       To 100%                                           Total           100.000                                                        ______________________________________                                    

    ______________________________________                                         REDUCED FAT RANCH DRESSING FORMULATION                                                         Typical      Range of                                          Ingredients Composition                                                                        Formula      Ingredients                                       Ingredients     Percent      Percent                                           ______________________________________                                         Soybean oil     24.500       15-28                                             Vinegar         8.000        4.0-12                                            Stanol esters)  5.750        4.0-8.0                                           Ranch seasoning 5.000        3.0-8.0                                           Sugar           4.000        2.0-7.0                                           Cultured buttermilk solids                                                                     1.400        0.2-3.0                                           Caprol ET       0.650        0.1-1.50                                          Lemon juice concentrate                                                                        0.450        0-2.0                                             Xanthan gum     0.450        0.1-0.60                                          Egg yolk        0.350        0-1.0                                             Polysorbate 60  0.300        0.1-0.30                                          Modified food starch                                                                           0.300        0-1.60                                            Propylene glycol alginate                                                                      0.215        0.05-0.5                                          Distilled mono- & di-                                                                          0.200        0-1.50                                            glyceride                                                                      Water           46.765       To 100%                                           Total           100.000                                                        ______________________________________                                    

Comparative Examples

The following examples demonstrate formulations which were found to be unstable when refrigerated. However, when the stanol ester was removed and the formulation reconstituted, the formulation was once again stable, even when refrigerated.

    ______________________________________                                         Ranch Style Salad Dressing                                                                       Unstable  Stable                                             Ingredients Composition                                                                          Formula   Formula                                            Ingredients       Percent   Percent                                            ______________________________________                                         Soybean oil, salad oil                                                                           40.000    45.750                                             Vinegar           6.000     6.000                                              stanol esters     5.750     0.000                                              Sugar,            4.500     4.500                                              seasoning         4.000     4.000                                              Cultured buttermilk solids                                                                       1.000     1.000                                              Cooking salt      0.400     0.400                                              Egg yolk, liquid, 10% salt                                                                       0.360     0.360                                              Xanthan gum       0.340     0.340                                              Propylene glycol alginate                                                                        0.160     0.160                                              Preservatives, colorings                                                                         Balance of                                                                               Balance of                                         vitamins and seasonings                                                                          formulation                                                                              formulation                                        Water             36.988    36.988                                             Total             100.000   100.000                                            ______________________________________                                    

    ______________________________________                                         FRENCH STYLE DRESSING FORMULATION                                                                Unstable  Stable                                             Ingredients Composition                                                                          formula   formula                                            Ingredients       Percent   Percent                                            ______________________________________                                         Soybean oil, salad oil                                                                           35.000    40.600                                             Sugar, fine granulated                                                                           17.500    17.500                                             Vinegar, 120 grain, white                                                                        6.000     6.000                                              distilled                                                                      Tomato Paste (.sup.˜ 31% solids)                                                           6.000     6.000                                              Stanol esters     5.600     0.000                                              Egg yolk, liquid, 10% salt                                                                       0.350     0.350                                              Xanthan gum       0.200     0.200                                              Propylene glycol alginate                                                                        0.100     0.100                                              Preservatives, colorings                                                                         Balance of                                                                               Balance of                                         vitamins and seasonings                                                                          formulation                                                                              formulation                                        Water             26.231    26.231                                             Total             100.000   100.000                                            ______________________________________                                    

    ______________________________________                                         TYPICAL THOUSAND ISLAND DRESSING FORMULATION                                                     Unstable  Stable                                             Ingredients Composition                                                                          formula   formula                                            Ingredients       Percent   Percent                                            ______________________________________                                         Soybean oil       35.000    40.600                                             Sweet relish      11.00     11.000                                             Sugar, fine granulated                                                                           9.000     9.000                                              Vinegar, 120 grain, white                                                                        6.000     6.000                                              distilled                                                                      Stanol esters     5.600     0.000                                              Tomato paste (.sup.˜ 31% solids)                                                           5.000     5.000                                              Egg yolk, liquid, 10% salt                                                                       0.400     0.400                                              Xanthan gum       0.300     0.300                                              Propylene glycol alginate                                                                        0.150     0.150                                              Preservatives, colorings                                                                         Balance of                                                                               Balance of                                         vitamins and seasonings                                                                          formulation                                                                              formulation                                        Water             25.580    25.580                                             Total             100.000   100.000                                            ______________________________________                                    

    ______________________________________                                         TYPICAL CREAMY ITALIAN DRESSING FORMULATION                                                      Unstable  Stable                                             Ingredients Composition                                                                          formula   formula                                            Ingredients       Percent   Percent                                            ______________________________________                                         Soybean oil, salad oil                                                                           33.000    38.750                                             Vinegar           9.200     9.200                                              Sugar             6.000     6.000                                              Stanol esters     5.750     0.000                                              Buttermilk        0.500     0.500                                              Eggs              0.400     0.400                                              Xanthan gum       0.320     0.320                                              Modified food starch                                                                             0.250     0.250                                              Water             38.240    38.240                                             Preservatives, colorings                                                                         Balance of                                                                               Balance of                                         vitamins and seasonings                                                                          formulation                                                                              formulation                                        Total             100.000   100.000                                            ______________________________________                                    

    ______________________________________                                         TYPICAL LIGHT RANCH DRESSING FORMULATION                                                         Unstable  Stable                                             Ingredients composition                                                                          formula   formula                                            Ingredients       Percent   Percent                                            ______________________________________                                         Soybean oil, salad oil                                                                           24.500    30.260                                             Vinegar,          8.000     8.000                                              Stanol esters)    5.750     0.000                                              Seasoning         5.000     5.000                                              Sugar             4.000     4.000                                              Cultured buttermilk solids                                                                       1.400     1.400                                              Lemon juice concentrate                                                                          0.450     0.450                                              Xanthan gum       0.450     0.450                                              Egg yolk          0.350     0.350                                              Polysorbate 60    0.300     0.300                                              Modified food starch                                                                             0.300     0.300                                              Propylene glycol alginate                                                                        0.215     0.215                                              Preservatives, colorings                                                                         Balance of                                                                               Balance of                                         vitamins and seasonings                                                                          formulation                                                                              formulation                                        Water             47.615    47.615                                             Total             100.000   100.000                                            ______________________________________                                     

We claim:
 1. A liquid food comprising:a cholesterol reducing amount of a sterol ester; an emulsifier or a hydrocolloid; and an effective amount of a fat crystal inhibitor selected from the group consisting of rolyglycerol esters of fatty acids, sorbitan esters of fatty acids, and polysorbates made from the reaction product of monoglycerides or sorbitan esters and ethylene oxides; to provide a stable emulsion.
 2. The food of claim 1 which is a salad dressing.
 3. The food of claim 2 wherein the emulsifier is selected from the group consisting of polysorbate 80, and polysorbate
 60. 4. The food of claim 3 wherein the emulsifier level is from about 0.01 to about 1.5 weight percent.
 5. The food of claim 3 wherein the crystal fat inhibitor level is from about 0.1 to about 3.0 weight percent.
 6. The food of claim 2 wherein the hydrocolloid is selected from the group consisting of xantham gum, propylene glycol alginate, modified food starches and cellulose derivatives.
 7. The food of claim 2 which contains from about 0.5 to about 1.5 grams of sterol ester per serving.
 8. The food of claim 1 wherein the emulsifier is selected from the group consisting of polysorbate 80, and polysorbate
 60. 9. The food of claim 1 wherein the hydrocolloid is selected from the group consisting of xantham gum, propylene yiycol alginate, modified food starches and cellulose derivatives.
 10. The food of claim 1 which contains from about 0.5 to about 1.5 grams of sterol ester per serving.
 11. The food of claim 1 which remains stable when refrigerated.
 12. The food of claim 1 wherein the emulsifier level is from about 0.01 to about 1.5 weight percent.
 13. The food of claim 1 wherein the crystal fat inhibitor level is from about 0.1 to about 3.0 weight percent. 